\\[-1.8ex] Soil Heterogeneity & $-$3.766$^{***}$ & $-$2.948$^{***}$ & $-$2.861$^{***}$ & $-$2.792$^{***}$ & $-$2.774$^{***}$ & $-$2.816$^{***}$ & $-$2.819$^{***}$ \\ 
  & (0.927) & (0.812) & (0.793) & (0.771) & (0.767) & (0.769) & (0.779) \\ 
\\[-1.8ex] 
Observations & 14,175 & 14,175 & 14,175 & 14,175 & 14,175 & 14,175 & 14,175 \\ 
R$^{2}$ & 0.577 & 0.595 & 0.596 & 0.599 & 0.600 & 0.601 & 0.602 \\ 
